The present invention relates to cameras capable of correcting blurring occurring due to camera movement or camera-shake (hereinafter referred to as blurring), and particularly to cameras capable of blurring correction which can perform automatic focusing control (hereinafter referred to as AF).
Cameras capable of correcting blurring have been proposed recently. As a camera-shake sensor in a camera capable of blurring correction, one which employs an angular velocity sensor is possible. The blurring correction is performed by detecting camera-shake amount of a camera employing an angular velocity sensor and driving a lens to correct it.
Recent cameras have an AF function. In a camera having an AF function, a lens is automatically driven for focusing on an object. Then, acceleration noise is produced in the camera-shake detecting sensor due to vibration of the motor and vibration of the driving mechanism. It was then recognized that the blur is not properly corrected because correct angular velocity outputs cannot be obtained accordingly.
Furthermore, in a camera capable of blurring correction, the blurring amount of image of an object to be photographed on film is corrected in exposure of the film. In order to correct the blurring amount of the object on the film, a blurring amount correcting lens provided in a group of lenses is driven at a speed necessary for correction.
In a camera capable of hand-shake correction, the hand-shake is corrected as described above. As compared to the performance of the blurring correcting means, however, the speed required for correction of a correcting lens for hand-shake correction is sometimes too fast for correction, or sometimes the amount to be corrected is so large that the correction is made insufficiently. In these cases, even with a camera having correcting means, there is a problem that the hand-shake cannot be sufficiently corrected, so that blurring exists in a picture.
In addition, cameras capable of flashlight emission and blurring correction have been proposed recently. Only one power source place generally exists in a camera, so that boosting for flash and driving of blurring detecting sensors are generally performed using a single power source in a camera capable of flashlight emission and blurring correction.
When a flash circuit is boosted by a power source, the voltage of a battery is likely to fluctuate, so that a problem might occur that the data provided by a shake detecting sensor such as an angular velocity sensor is not correct due to the influence.
Accordingly, it is an object of the present invention to perform blurring correction correctly in a camera capable of detection of camera-shake.
It is another object of the present invention to perform blurring correction as much as possible in a camera capable of detection of camera-shake.
The above objects of the present invention are attained by a camera capable of camera-shake detection including the following elements. That is, a camera according to the present invention includes a camera-shake amount detecting sensor for detecting a camera-shake amount of said camera, a blurring corrector for correcting blurring of said camera on the basis of said camera-shake amount, a focus adjusting optical system for focusing on an object image, a driver for driving the optical system, and a controller for controlling the driver and the blurring corrector so that the blurring corrector does not use outputs of the camera-shake detecting sensor when the optical system is being driven.
In the period in which vibration noises are produced because the optical system is driven, the blurring correcting device does not use outputs of the camera-shake detecting sensor. Accordingly, wrong detection of blurring amounts is avoided. As a result, in a camera capable of camera-shake detection, correct blurring correction is possible.
Preferably, a camera according to the present invention includes an exposure amount controller for controlling exposure to film, a camera-shake detecting sensor for detecting said camera-shake amount, a blurring corrector for correcting image blurring caused by the camera-shake in response to an output of the camera-shake detecting sensor, a determining device for determining whether the camera-shake can be properly corrected or not, an auxiliary light means for lighting the object, and a controller for making the auxiliary lightening device emit light when the determining device determines that the camera-shake cannot be properly corrected in the exposure.
Generally, a blurring amount is expressed as a product of exposure time and blurring velocity. When the above-identified exposure time or blurring velocity exceeds a correctable amount, the determination device determines that blurring correction is impossible. In this case, the blurring amount can be reduced by reducing the exposure time. If the exposure time is reduced at that time, however, the exposure amount decreases. Therefore, in the present invention, flashlight is emitted to compensate for the insufficient exposure amount due to the decrease in exposure time.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.